NaI 149.89

Sodium iodide.
Sodium iodide [7681-82-5].

Packaging and storage— Preserve in tight containers.

Identification— Asolution (1in 20)responds to the tests for Sodium á191ñand for Iodide á191ñ.

Alkalinity— Dissolve 1.0g in 10mLof water,and add 0.15mLof 0.10Nsulfuric acid:no red color is produced by the addition of 1drop of phenolphthalein TS.

Water,Method Iá921ñ: not more than 2.0%.

Iodate— It meets the requirements of the test for Iodateunder Potassium Iodide,100mg of Sodium Iodide being used in the control.

Thiosulfate and barium— It meets the requirements of the test for Thiosulfate and bariumunder Potassium Iodide.

Potassium— Asolution of 1.0g in 2mLof water yields no precipitate with 1.0mLof sodium bitartrate TS.

Heavy metals á231ñ— Dissolve 2.0g in 25mLof water:the limit is 0.001%.

Limit of nitrate,nitrite,and ammonia— Add 5mLof 1Nsodium hydroxide and about 200mg of aluminum wire to a solution of 1.0g of Sodium Iodide in 5mLof water,contained in a test tube of about 40-mLcapacity.Insert a pledget of purified cotton in the upper portion of the test tube,and place a piece of moistened red litmus paper over the mouth of the tube.Heat in a steam bath for 15minutes:no blue coloration of the paper is discernible.

Organic volatile impurities,Method Iá467ñ: meets the requirements.

Assay— Weigh accurately about 500mg of Sodium Iodide,and dissolve in about 10mLof water.Add 35mLof hydrochloric acid,and titrate with 0.05Mpotassium iodate VSuntil the dark brown solution which is produced becomes pale brown.Add 1mLof amaranth TS,and continue the titration slowly until the red color just changes to yellow.Each mLof 0.05Mpotassium iodate is equivalent to 14.99mg of NaI.

Expert Committee:(PA1)Pharmaceutical Analysis 1

USP28–NF23Page 1786

Phone Number:1-301-816-8379